Wanna ask, if I already got an Xbox Live account created from my Xbox 360 playing, can I use "PURCHASE USING LOCAL CREDIT CARD/DEBITCARD IN MARKETPLACE" trick?

Owh I see. I take it that it that didn't work.

What's up with closing apps in the background? I believe it's the contest rule because app launches much faster if it's in the background.

no example if you loaded angry bird game on iOS even its in the background u run another app and switch back it will load from the start again unlike windowsphone it loads back where u stop.

Yeah. For apps on WP7, it's quite a bugger. It can only have that kinda previous state resume done via the longpress backbutton but not if you repress the app again. I have a quibble with this after spending much time with WP7. It is different with the browser though as it still keeps the tabs (surely they had to). But it bugs me when toast notifications only can get you to the main view and not the specific page. It's quite annoying especially when you click on a whatsapp message and will have to wait for it to reload rather than straightaway go to that chat. I hope they fix this issue for WP8.

The lack of gyroscope is made up for by internal compass. So you shouldn't feel so "different" from those with a gyroscope. If you act as a tripod, Photosynth will work wonders provided your angle remains the same.